This K23 Mentored Patient-Oriented Career Development award application is designed to provide the education and skills necessary for the principal investigator to transition from population-based epidemiologic and health services research to health services intervention trials. The principal investigators' short-term research goal is to gather the data necessary to inform the development of a health system intervention to improve the appropriate identification of depression and the initiation of timely evidence-based treatments for depressed adolescents in primary care settings. Her long-term goal is to gain the skills and experience necessary to be a competitive researcher in the area of health services interventions to improve the identification and appropriate treatment of adolescent mental health conditions in primary care settings. To assist her in these goals, she has identified two mentors with complementary expertise in adolescent depression and health services interventions to improve the treatment of depression in primary care. The educational plan outlined in this application includes didactic and experiential training in three topic areas: 1) qualitative research methods; 2) child and adolescent psychopathology and treatment; and 3) health services intervention design, implementation and assessment. The three projects outlined in this application build on the training objectives and specifically aim: 1) to develop an inductive model from ethnographic interviews that promotes an understanding of how adolescents seek and receive treatment for depression in primary care settings, 2) to evaluate clinical and demographic predictors of depression persistence in primary care in order to develop a case definition for adolescent who would most benefit from an intervention, 3) to determine the acceptability and feasibility a health system intervention, based on the Chronic Care Model, to improve primary care treatment for depressed adolescents. At the completion of this K Award, the primary investigator will have obtained the skills and experience necessary to design, obtain funding for, and implement a large-scale health services intervention to improve the management of adolescent depression in primary care settings.